The collapse of the Afghan Government and the rapid takeover by the Taliban has sent shockwaves through the Armed Forces community.
The Taliban effectively seized control of Afghanistan after the capital city Kabul fell to the group, with 600 UK personnel deployed to the country last week to help UK nationals leave the country.
Paul 'Pen' Farthing, a former Royal Marine who founded an animal rescue charity in Afghanistan, told Forces News the situation in the country has left him "embarrassed to be British and part of what we have just done".
"This is just shocking," he said.
"We didn't even attempt to negotiate with the Taliban.
"The only deal we made was 'yeah we're going to leave, don't shoot us in the back' – that was it.
"We could have forced the Taliban to the table and then things would be so much different today than what they are.
"This is just pure desperation here and I have no words," he added.
Mr Farthing, who is based in the country, said there is "no way" he is leaving Afghan staff to an "absolutely horrendous fate, especially our young female staff".
"I mean, the potential is they'll be married off to a Taliban fighter, they'll never be allowed out of the house and that is where they will stay for the rest of their lives," he said.
"They do not deserve that. We gave them hopes, aspirations for the future and then we just said 'no, we're leaving."
Watch: Emotional Defence Secretary admits 'some people won't get back' from Afghanistan.
Robert Clark, an Army veteran and defence analyst, told Forces News the collapse of Afghanistan "is something that will touch the veteran community and those still serving to the very core of their beliefs".
He added "the global war on terror defined" his generation of Armed Forces personnel.
"To see the hard work that has been achieved in Afghanistan over the last 20 years almost undone overnight, in the space of around 72 hours, is just, it's actually, beyond upsetting and frustrating to see.
"It's incredibly painful to watch I'm afraid," he added.
Nikki Scott, war widow and founder of Scotty's Little Soldiers, told Forces News the events have "stirred up so many different emotions" for herself and her children.
Her husband, Corporal Lee Scott, was killed in Afghanistan in 2009 and she set up the charity "to support bereaved British Forces children and young people".
She said it is "such a difficult time for the families" that the charity supports.
Watch: Military anger over Afghanistan pull-out as Taliban advances.
"It is so important that people remember how personal this is for the families who have experienced the death of a loved one due to serving in Afghanistan," she said.
"Like my family, you can be so proud of the service your parent has given to our country," she said.
She added that she is "incredibly proud of the work" her husband and all those who served in Afghanistan did, and said "whatever happens in the days that follow, that legacy will live on forever".
Graham Knight, the father of 25-year-old RAF Sergeant Ben Knight, who was killed when his Nimrod aircraft exploded in Afghanistan in 2006, said he is "not surprised the Taliban have taken over".
"As soon as the Americans and the British said they were going to leave, we knew this was going to happen," he said.
"The Taliban made their intent very clear that, as soon as we went out, they would move in."
Watch: Afghanistan – world watches as Taliban enters Kabul.
He went on: "As for whether people's lives were lost through a war that wasn't winnable, I think they were.
"I think the problem was we were fighting people that were native to the country.
"We weren't fighting terrorists, we were fighting people who actually lived there and didn't like us being there."
Ian Sadler, whose 21-year-old Trooper son Jack died when his Land Rover struck a mine in Afghanistan in 2007, said he was surprised the US and allied forces "had so much confidence in the Afghan National Army".
"Why did they think the Afghan National Army would be able to keep the Taliban back based on just numbers alone? Why did our Government and allies have so much confidence in them?
"It proved to be rubbish, really," he said.
"Why did the president say Kabul will never fall when, at the same time, he must have been planning his escape?
"To pull them out so quickly like that… I would have thought it would have been more of a strategic advantage to reduce the British and American influence.
"When the NATO forces were pulled out so suddenly, the Afghan National Army were left without any direction."
However, the mother of a Royal Marine killed in Afghanistan said her son "did not die in vain" as she said he helped make the country a better place before the return of the Taliban.
Watch: What happens now the Taliban is "in control"?
Corporal Danny Winter, 28, was killed along with Captain Tom Sawyer, 26, of the Royal Artillery, in Gereshk, central Helmand, on 14 January 2009.
And Cpl Winter's mother, Carolyn Hughes, wrote on his Facebook memorial page: "Danny and all the armed forces of the countries involved made a huge difference to a wild, war-torn country.
"Because of them, terrorist attacks on our country were avoided and countless lives were saved.
"The women of Afghanistan were safe to walk the street and get an education, something that had always previously been denied.
"People were happy and felt safe."
Mrs Huges said she is "extremely proud that my son played a small part in achieving this".
The differing – and emotionally charged – views come after John Baron, the Conservative MP for Basildon and Billericay, called on Prime Minister Boris Johnson to apologise to bereaved service families and personnel who are "still paying the price" for the UK's handling of the mission in Afghanistan.